Color cinematography



Sept. 17, 1929. K, ARTIN 1,728,426

COLOR G I NEMATOGRAPHY Filed Feb. 17, 1926 Patented Sept, 17, lQZQ CQLORCINEMATOGRAPHY Application filed. February 17, 1926, Serial No. 88,812,and in Germany April 11, 1925.

This invention relates to a color cinematographic apparatus.

lln my invention -l use a film, which may be of the standard size andtravels vertically up 5 wards or downwards in the usual manner,

each normal frame being divided longitudinally to carry twocomplementary color records, but the pictures are placed side uppermost,and in projecting the images through 10 appropriate color filters (sayred and green) an optical system is used whereby the images are rotatedthrough 90, to place them up right, and are at the same time moved apartto enable each to be projected through an 15 objective of ample size forgiving adequate intensity of light. If instead of only two colors threeor four colors are to be used, a frame with two complementary records,for two of the colors, is followed by one with two records as made bylight of the third color or by light of the third and fourth colorsrespectively, and all the images are rotated through 90 as described.

It will be noted that with the apparatus 2 which I shall describe eachcomplementary picture is produced, and projected, through an objectivewhose capacity in regard to intensity of light can be utilized to thefull.

In the annexed drawings,

Figs. 1 and 2 are two views of one of the prism systems used in myapparatus,

Figs. 3 and 4 aretwo plan views of the opti cal system in two difi'erentpositions, and

Fig. 5 is a front View of the prism systems and the films, the positionsof the objectives being indicated in dotted lines.

Figs. 1 and 2 show a prism system, of which one is provided for eachcomplementary picture, that is to say for each objective. It comtoprises three rectangular prisms a, b, 0 and each of two faces or" theprism Z2 is cemented to one face or one of the other prisms. The twosystems are disposed so that the exposed faces of the prisms a areapportioned,respectimely, to the two complementary pictures 03, 0? ofthe film al in a frame of standard size, and the exposed faces of theprisms 0 face the objectives e.

It will be apparent that with one of the so prism systems heldas shownin Fig. 2, an arrow placed as shown behind the prism a would be viewedfrom the ifront,through the prism a, in the manner indicated in thedrawing, the image being rotated through 90, and this is required forthe purposes of the invention, as already explained. a

In Fig. 3 a source of light is indicated at f, with a condenser g in thepath of the beam. ll may also use a cylindrical dispensing lens h, asshown, or a special condenser system, but these are subsidiary mattersnot in themselves forming part of the invention,

If only two color partial pictures are to be used, the successivepartial pictures (Z (V will be taken and projected through red and greenfilters for example. @n the other hand, it four complementary colors areto be used each pair of complementary partial pictures, for example redand green will be followed by a different pair of complementary partialpictures, for example blue and yellow. lhis arrangement is symbolicallyindicated in Fig. 5 in which d indicates a partial picture taken througha red filter, d a partial picture taken through a green filter, dthrough a yellow filter and (2 through a blue filter.

lin order to uniformly screen the two complementary pictures during thefeed of the film a single shutter i of the usual type may be used,covering both pictures.

lit will be understood that an ordinary pro 'jecting apparatus, forblack and white work,

gan be adapted for the purposes of my method, by removing the objective,and per haps also the condenser system or part of it, and substitutingthe double objective and prism systems which I have described, with suchcondenser element or elements as may be required. To change back toblack and white work is equally simple. llhe color filters p, p may withadvantage be fixed to the ob jective holder, at on which are mounted thecolor objectives e, e, and. the objective or for black and whiteprojection, and the changeover can then be made very quickly and easily,particularly if the parts are arranged to slide into and out of positionas on the slide 7'. it mention this because it may sometimes be desiredto show black-and-white and colored pictures alternately, and films forthe former and latter respectively may even be joined together, in onereel.

What I claim is:

Apparatus for cinematographically projecting pictures, comprising asource of light, a Vertically travelling film divided into frames, eachframe comprising a pair of partial pictures constituting complementarycolor records, said partial pictures being side uppermost. a pair ofprism systems on the side of said film opposite from said source oflight for rotating the images of said partial pictures 90 and spreadingthem apart, objectives and color filters for said prism systems, saidprism systems, objectives, and color filters being mounted on' ashiftable frame, and an optical system for blaclcand-White Work alsomounted on said shiftable frame, the arrangement being such that eitherthe color optical system or the black-and-White optical system can bemoved into the path of the projecting light.

In testimony whereof the foregoing specification is signed.

KARL MARTIN.

